1. Field of the Invention
The present invention relates to a safety device for breaking power to a source of household electrical power. In alternative embodiments, the device plugs into a standard wall receptacle, or supplants a standard receptacle. Under normal conditions, the novel device passes power to power cords from appliances which are plugged into the safety device, and discontinues this power responsive to an alarm signal from a smoke detector.
2. Description of the Prior Art
In the event of fire, it is desirable to discontinue electrical power from certain electrical appliances operating in a building. In some cases, an appliance may be the source of an alarm signal generated by a smoke detector. For example, a cooking device, such as a fryer or oven which is unattended may emit smoke, which will then be sensed by a smoke detector.
In other cases, the appliance, which may operate innocuously under normal conditions, may exacerbate an incipient fire. A fan or the like, paint or solvent spraying equipment, air compressors, and the like which may be operated in a building susceptible to fire, are further examples of electrically operated equipment which may benefit from such protection.
U.S. Pat. No. 4,171,944, issued to Jack B. Hirschmann on Oct. 23, 1979, discloses a system for shutting off a powered appliance responsive to detection of smoke. In this invention, a smoke detector produces a signal which is employed to operate a relay controlling electrical power to the appliance, a furnace.
A device disposed in series within an electrical supply cord, having a plug for insertion into an electrical receptacle, is seen in U.S. Pat. No. 5,019,935, issued to Ikuro Nakamura on May 28, 1991. Detection of the alarm condition is accomplished by monitoring current flowing in the supply cord.
A shutoff arrangement for a specialized electric lamp, typically a high intensity discharge lamp, is disclosed in U.S. Pat. No. 4,973,881, issued to Thomas Haraden et al. on Nov. 27, 1990. Damage to an outer surrounding member causes a mechanical linkage to disconnect power to the lamp.
Sonic detectors for detecting an alarm condition by sound and generating a response are known. U.S. Pat. Nos. 4,991,145, issued to Steven G. Goldstein et al. on Feb. 5, 1991, and 5,162,777, issued to Klaus-Peter Kolbatz on Nov. 10, 1992, are representative. Both of these inventions employ a microphone for detecting sonic manifestation of an alarm condition.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.